This application claims the benefit of Korean Patent Application No. 2000-75406 filed on Dec. 12, 2000 in the Korean Industrial Property Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a disc drive used as an auxiliary memory for a device such as, for example, a computer, and more particularly to an actuator of the disc drive to fly an optical head or a magnetic head toward a disc to record and/or reproduce information to and/or from the disc.
2. Description of the Related Art
Generally, among disc drives used by a user to record and/or reproduce information onto/ from discs, a hard disc drive is especially used in personal computers as an auxiliary memory. The hard disc drive, as generally known, uses a magnetic recording principle that records and/or reproduces desired information by axially moving an optical head on a disc that is coated with a magnetic material.
Meanwhile, there has been growing demands for compact-sized hard disc drives that can be employed in portable appliances such as laptop computers, digital cameras, or the like, and also in larger memory capacity devices. In order to satisfy such demands, an optical recording and/or reproducing method has been employed instead of the magnetic recording method.
FIG. 1 is a view schematically showing an example of a conventional hard disc drive, in which an upper cover (not shown) is opened. As shown in FIG. 1, in the conventional hard disc drive, a ring-shaped magnetic disc 10 is mounted on a rotary shaft 30 of a spindle motor (not shown) that is mounted on a base 20. The magnetic disc 10 is rotated on the rotary shaft 30 of the spindle motor at a high speed. Also, an actuator 100, for which a magnetic or optical head slider (h) is attached to a leading-end thereof, is mounted on an edge of the base 20 to be pivoted on a pivot (p) by driving of a voice coil motor (VCM) 110.
The actuator 100 includes a swing arm 120 connected to the pivot (p), and a load beam 130 connected to the swing arm 120. The lower end of the load beam 130 is connected to an elastic member, i.e., a flexure 140, while the head slider (h) is mounted on a leading end of the flexure 140.
As shown in FIG. 2, the head slider (h) is floated from adjacent to the disc 10 by a predetermined height distance, by air current produced by rapid rotation of the disc 10 during the driving of the hard disc drive. In a state that the optical head slider (h) is floated adjacent to the disc 10, the head slider (h) is moved across the disc 10 toward the inner side of the disc 10 by pivoting of the actuator 100, and reproduces recorded data from the disc 10 or records new data on the disc 10. Reference numeral 40 refers to a cover of the disc drive.
According to the above mentioned conventional hard disc drive, if external shock or vibration is applied to the hard disc drive in operation, as shown in FIG. 3A, the load beam 130 vibrates in a bending motion towards and away from the disc 10. Due to the vibration, the load beam 130 collides with the cover 40 (see FIG. 3A), and the head slider (h) collides with the disc 10, as shown in FIG. 3B, repeatedly. Accordingly, there can be damage caused to the data stored in the recording surface of the disc 10, or damage to the actuator 100. Especially for disc drives employed in the portable appliances such as laptop personal computers, camcorders, digital cameras, or the like, which are more frequently subject to the external vibration or shock, there is a high possibility of damage to the disc 10 and the actuator 100.
Accordingly, it is an object of the present invention to provide an actuator to be used with a device such as a disc drive that has a shock damping device to dampen the vibration of a load beam caused by external shock to the device.
Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
The above and other objects are accomplished by providing an actuator to be used with a disc drive having a shock damping device in accordance with the present invention, including an electro-magnet disposed on a cover of the disc drive, a magnetic material disposed on a load beam of the actuator and opposite to the electro-magnet, and a driving control portion that controls a driving of the electro-magnet by detecting an upward and downward vibration of the load beam that is caused by external shocks.
The driving control portion includes an interference sensor disposed on the cover, and an interference member disposed on the load beam, opposite to the interference sensor.
According to another aspect of the present invention, the driving control portion includes a timing switch to adjust a time for supplying electricity to the electro-magnet. Meanwhile, the driving control portion controls the timing switch in a manner such that the electricity is supplied to the electro-magnet for a predetermined time when an amplitude of vibration of the load beam is detected to be out of a predetermined range of amplitude of vibration.
According to still another aspect of the present invention, there is provided an insulating material disposed between the interference member and the load beam. Thus, when the load beam is vibrated by external vibration or shock to the disc drive, electricity is supplied to the electro-magnet, securing the load beam to the cover until the vibration ceases. Accordingly, even when there is external vibration or shock applied to the disc drive, possible damage to the disc or the actuator can be prevented.